The adoption of electronic mail (email) has occurred at an unprecedented pace, and now, among routine computer users, most have an email address. In fact, many have more than one email address, e.g., one for work and another for home, primarily because email offers unparalleled convenience of written communication. However, with the widespread adoption of email, a proliferation of junk or otherwise unwanted email, or “spam,” has also occurred. Currently, of the hundreds of millions of email messages sent each day, about 30% of those messages may be expected to be unwanted email.
Many companies have developed in recent years to combat the problem of unwanted email by providing email filtering that attempts to identify and discard unwanted email. Early approaches to combating unwanted emails have involved software that resides on a destination email server. Unfortunately, such a solution does not scale well since, generally speaking, installing and maintaining email filtering software on email servers grows increasingly difficult as the number of email servers multiplies.
Other older systems for blocking spam or viruses include systems that populate decoy email addresses around the Internet, where the decoy email addresses act as spam collectors. Human editors then review the messages that come in, catalog them, and create a database of such junk-mail messages and their checksums. The created database is then promulgated to subscribers of the service, and each message received at the customer premises is checked against the virus/spam database. Unfortunately, such detection and monitoring of the Internet for new virus and spam messages is not in real time, and the customer premise email server must still receive all of the spurious emails and then analyze all the incoming emails to see whether there is a match in the database.
A more recent approach to blocking unwanted email involves the intercepting of incoming messages before they reach the destination server, and filtering out the unwanted messages. An example of such a system is found in U.S. Pat. No. 6,650,890, which is commonly assigned with the present disclosure and incorporated herein by reference in its entirety. Moreover, once incoming messages deemed unwanted have been intercepted and stored (“quarantined”), notification messages may be sent to the intended recipients informing them of the quarantined messages. Examples of such quarantine summary messages may be found in U.S. Pub. Application 2003/0158905, which is also commonly assigned with the present disclosure and incorporated herein by reference in its entirety. Once notified of quarantined messages, a user may then log onto a message center via a computer network, in order to manage the quarantined messages or even to manage personal settings for that particular user's email filtering needs. Since interception of unwanted electronic messages has proven to be highly efficient, improvements in the way quarantined messages are managed are also beneficial for overall efficient in the war against spam, viruses, and other unwanted messages.